Lundquist



March 20, 1956 1. LUNDQUIST 2,738,926

CARRIAGE CUSHIONING MEAN-S FOR CALCULATING MACHINES Filed Aug. 8, 1952INVENTOR /NGEMAR LUNDQUIST BY A: :ORNEY lifted States Patent CARRIAGECUSHIONING MEANS FOR CALCULATING MACHINES Ingeznar Lundquist, EastOrange, N. 1., assignor to Monroe Calculating Machine Company, Orange,N. 1., a corporation of Delaware Application August 8, 1952, Serial No.303,267

2 Claims. (Cl. 235-63) The invention relates to carriage shiftingmechanism for calculating machines and more particularly to improvementsin carriage shifting mechanism of the type disclosed in Patent No.2,473,471 issued on June 14, 1949, to Herman Gang. This type of shiftmechanism is adapted to raise a pivotally mounted carriage to disengagethe register transmission gears in the carriage from those in the fixedframe of the machineto thereby permit denominational shift of thecarriage. The ar rangement is such that the carriage is raised duringthe first half step of a denominational shifting operation, and duringthe second half step of the operation, gravity assisted by a pair oflocators moves the carriage downwardly to reengage the registertransmission gears. Normally, the downward movement of the carriagewould be accelerated and considerable objectionable noise would resultfrom sudden arrest of the movement at the completion of the shiftingoperation. To minimize this noise, the aforenoted patent discloses acushioning arrangement comprising a governor which retards the downwardmovement of the carriage. The governor, however, is effective throughoutsubstantially the entire downward movement of the carriage and this hasbeen found to slow the shifting operation.

The present invention provides carriage cushioning means which issubstantially ineffective to control the downward movement of thecarriage until near the end of such movement in a shifting operationeffected by mechanism of the type referred to above. The devices of theinvention prevent acceleration near the end of the downward movement ofthe carriage and therefore do not substantially reduce the speed of theshifting operation while appreciably reducing the noise attendanttherewith. The invention, however, will best be understood from thefollowing description with reference to the accompanying drawings inwhich:

Fig. l is a vertical section through the machine embodying the inventionwith the parts in normal position.

Fig. 2 is a detail fragmentary view taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary vertical section showing parts of the inventionshown in Fig. 1 in an operated position.

The carriage 1 is provided at its rear with a shaft 3 extending betweenthe end plates thereof and slidably and rotatably mounted in the sideframes of the machine. The carriage is therefore adapted to be raised atits forward edge to disengage the gears 5 of the wheels 7 of the productdividend register from the transmission gears 9 so that the carriage maybe longitudinally shifted. The transmission gears 9 which are mounted inthe body of the machine are driven by digital and tens carry actuatingmechanism (not shown) as is well known in the art.

As fully disclosed in the aforenoted patent, carriage 1 isdenominationally shifted upon a 180 turn of a shaft 11 which isjournaled in suitable bearings beneath the keyboard of the machine.Shaft 11 may be manually rotated by a handle 12 (Fig. l) or may berotated auto- 2,733,925 Patented Mar. 20, 1956 matically as described inthe abovenoted patent to which reference is made for such operation.

The means whereby carriage 1 is shifted upon rotation of shaft 11includes a double arm crank 13 mounted at the rear end of the shaft andprovided with a pair of diametrically disposed rollers 13. The rollers13 are equidistantly spaced from shaft 11, and when the carriage is inits normal lowered position, the rollers lie in a horizontal plane(Figs. 1 and 2) and respectively engage a scalloped recess 15 in thelower edge of a rail 17 at the forward edge of the carriage. Rollers 13,therefore, act to support the forward edge of the carriage when it is inits normal lowered position.

Crank 13 is rotated a half turn clockwise (Fig. 2) to effect a rightshift of one order and counterclockwise to effect a left shift. Whencrank arm 13 is rotated clockwise, for example, the leftmost roller 13'in engagement with a recess 15 will, through the first of travel, raisethe carriage pivotally and at the same time move it toward the right.During this movement, the rightmost roller 13' of crank arm 13 will bemoved downwardly from engagement with its recess in rail 17 as theforward edge to the carriage is moved upwardly. When crank 13 has passedthe 90 point, no further application of power to shaft 11 is necessaryto complete the shift, as the weight of the carriage assisted by a pairof locators, to be described, will urge said crank further in clockwisedirection to complete the half turn as the carriage moves downwardly andto the right into shifted position.

Each locator comprises a lever 19 fulcrumed to the inner side of theleft and right side frames of the machine respectively. Each lever 19 isurged clockwise by a spring 19' and has pivoted at its rearward end anupstanding arm 21, which at its upper end has a U-shaped jaw 21'embracing carriage rail 17 and through which said rail is longitudinallyslidable in the shifting of the carriage. Therefore, as carriage 1 movesdownwardly in the shifting operation, the locators comprising levers 19and arms 21 will insure the completion of such movement and of thecarriage shift operation. As disclosed in the aforenoted patent, thelevers 19 are moved against fixed stops at the conclusion of a shiftingoperation. The engagement of levers 19 with these stops and theengagement of the disengaged roller 13' of crank 13 with a recess 15 atthe conclusion of a shifting operation result in the objectionable noiseheretofore noted.

The cushioning means of the present invention for controlling downwardmovement of the carriage comprises a pair of control trains of similarconstruction and operation including each pair of levers 19 and arms 21respectively. Therefore, only one of the control trains and itsoperation will be described. Each control train comprises a normallydepending crank 29 (Fig. l) fulcrumed on the inner side frame of themachine. Pivotaliy connected at its lower end with crank 29 is a link 23which at its upper end has a slot 23' engaged by a pin 25 whichpivotally connects lever 19 and arm 21 of the associated locator. Whenthe parts are in normal position (Fig. 1), pin 25 engages the lower endof slot 23 and locates link 23 so that it is in dead center relationwith crank 29. A sprin 27 biases link 23 toward the right and to a muchlesser degree upwardly. The force of the spring 27, therefore, tends torotate crank 29 counterclockwise, and through link 23 and arm 21, toraise the forward edge of carriage 1. The force of spring 27, however,is not great enough to overcome the force of spring urged lever 19 orthe weight of the carriage alone. The carriage, therefore, is normallymaintained in its lowered position by gravity and by the urge of thelocators.

When the forward edge of carriage 1 is moved upwardly in a shiftingoperation, arm 21 of the locator will be moved upwardly therewith,thereby rocking lever 19 counterclockwise against the tension of itsspring. Although link 23 and crank 29 are at dead center position, thestart of this movement is allowed by slot 23 which permits upwardmovement of pin 25. However, as soon as pin 25 is moved from engagementwith the bottom of slot 23, spring 27 will be permitted to rock link 23counterclockwise about pin 25 and thereby rock crank 29 alsocounterclockwise to raise link 23 and reengage the bottom of slot 23with pin 25. As the forward edge of the carriage completes its upwardmovement, the bottom of slot 23' will remain engaged with pin 25 as link23 and crank 29 are rocked by sprin 27 to the position shown in Fig. 3.

As crank 13 passes through its 90 position and the forward edge ofcarriage 1 starts to move downwardly, locator arm 21 will also be moveddownwardly with the carriage by spring urged lever 19. Therefore, pin 25connecting lever 19 and arm 21 will, by engagement with the bottom ofslot 23', move link 23 downwardly and crank 29 clockwise from theposition shown in Fig. 3. From an inspection of Fig. 3, it will be seenthat, at the beginning of this movement, there will be little or noopposition thereto by spring 27 for the reason that, at this time,clockwise movement of crank 25 will lower its pivotal connection withlink 23 quite rapidly but will move the connection very slowly towardthe left to thereby tension spring 27. Furthermore, it will be seen thatspring 27 at this time has substantially no tendency to move link 23upwardly. However, as the forward edge of carriage 1 approaches itsnormal lowered position, a given downward speed of movement of link 23will rotate crank 29 at an accelerated rate of speed for the reason thatits pivotal point of connection with link 23 must move more rapidly tothe left toward its dead center position to permit a given downwardmovement of arm 23. At this time, therefore, spring 27 will be rapidlytensioned, thereby tending to prevent the above-described accelerationof the clockwise movement of crank 29. Therefore, as the forward edge ofcarriage l is moved to its lowermost position, such rate of movementwill be appreciably checked, and the parts will be brought to rest withlink 23 and crank 29 in dead center position. It will be noted thatlever 19 of the locator is not provided with a fixed stop as disclosedin the aforenoted patent. Such a stop is unnecessary for the reason thatlever 19 and its connected arm 21 are brought to rest in their properpositions by pin 25 in engagement with the lower end-of slot 23'. noisewhich would normally result at the termination of a carriage shiftingoperation is substantially reduced by eliminating a fixed stop for lever19 and by preventing acceleration of the carriage during the latterportion of its movement as it is lowered to normal position.

It has been found that normally the aforedescribed It will be seen,therefore, that carriage shifting and cushioning means operatessatisfactorily without application of spring power to locator levers 19,and that spring power is applied only to assure operation in the eventof binds etc. in the mechanism. If the mechanism is operated withoutspring power applied to levers 19, the rear arms of the levers act onlyas guide supports for pins 25 connecting arms 21 and links 23. When themechanism is so operated, arms 21 are moved downwardly by the lower edgeof rail 17 engaging the lower faces of the jaws of said arms as thecarriage is moved downwardly by gravity. Otherwise, the operation is thesame as hereinbefore described. Furthermore, it will be apparent thatcertain changes may be made in the shapes and arrangement of the partswithout departing from the principles of operation, and that the tensionof springs 27 may be regulated in accordance with the weight and inertiaof the parts and degree of cushioning desired. It will be understood,therefore, that the invention is to be limited only insofar asnecessirated by the scope of the appended claims.

I claim:

1. In a calculating machine having a carriage pivotally and slidablymounted on the fixed frame of the machine, and means fordenominationally shifting said carriage including means for raising saidcarriage pivotally and then permitting said carriage to be restoreddownwardly by gravity; means for controlling the downward movement ofsaid carriage, comprising a crank mounted on the fixed frame of themachine, a linkage connecting said crank with said carriage and operableto rotate said crank toward a horizontal position upon raising of saidcarriage and to restore said crank toward a vertical position upondownward movement of said carriage, and spring means for biasing saidcrank toward horizontal position.

2. In a calculating machine having a carriage pivotally and slidablymounted at its rear on the fixed frame of the machine, means fordenominationally shifting said carriage including means for raising saidcarriage pivotally and then permitting said carriage to be restoreddownwardly by gravity, and a carriage locator comprising a spring urgedlever mounted on the fixed frame of the machine and an arm havingpivotal connection at one end with one arm of said lever and slidingconnection at its other end with the front of said carriage; means forcontrolling the downward movement of said carriage, comprising a crankmounted on the fixed frame of the machine, a link connecting said crankwith said one end of said arm, and spring means for biasing said crankin opposition to said spring urged lever.

References Cited in the file of this patent UNITED STATES PATENTS HillMar. 3, 1925

